Filter



vOttt. 9, 1945. f w B PUMPHREY 2,386,506

FLTER v 'Filed Jan. 24,v 1944 Patented Oct. 9, 1945 UNVI'EDv STATES PATENT OFFICE 1 v 2,386,506 I f FILTER ywiuiam iz. rumphrey, oakland. Calif. Amilicatinsanuary 24, m44, serial No. 519,557 y11 claims. (o1.2 10'1o4) 1 Thisinventi'cm, a filter, is .an/improvement over conventional `types of nlters' in that it employs a series :of lter stages leach of a different filter; medium and vdifferent 'degree `of perviousness; inthat only-:oneof the several ilter ,stages ever requires cleaning or renewal and .that at very infrequent intervals, 4with cleaning or renewal .easily and .quickly accomplished; in that'filtering is carried out under pressure without exerting. any. pressure on the filtrate container; that the amount of lil-trate is easily adjusted to suit the normal demand;A that any normal excess is drained from the bottom of the container; and that there is nio possibility off'contamination of the nitrate from extraneous sources:

The 'objects and advantages of the invention are as follows:

First, to provide a iilter of simple construction and of .a compact size, and'which will filter liquids with the highest-,degree of 'eiiiciency Second, to provide a filter which is operated under pressure and 'which is regulatable to suit the demand, and which vunder'regulated conditions willr discharge .any normal excess of vIiltrate during periods ofsubnormaldemand, to waste .of three filter medium-sare employed, ywith the li-rst consisting of a granular loose material, and the others two different typesl of pervious molded materials of respectively lesser degrees of perviousness and increased ltering areas, sealed in their respective positions.

Fifth, to provide a citer in which the chai niteri ing medium consists of a dome-shaped form of slightly vpervious material, with the inside `of the domeforming the discharge side.

Sixth, to provide a filtrate Acontainer with a central riser pipe for discharge of kany great excess of filtrate, and to provide a tubular Ydischarge member extending from the lowest portion of the container externally of the riser to a point adjacent the top inside of the riser so as to normally discharge excess filtrate from the bottom of the container.

Seventh, to provide the riser with avfluid trap to permit discharge of excess ltrate to kWaste while simultaneously preventing any contamina'- tion by air orgases of the filtrate by air or gases the uppersection normally sealing the' passages, with the passages openable for complete drainage of thel container. through part unscrewing of the upper section from the lower section.

Other objects and advantages of the invention will'becomeapparent'as the following description is read on .the drawing forming apart of this specification, in' which:

Fig. 1 is a sectional elevation through the Ainvention.

Fig-2 is asection Itaken on line 2--2 of Fig. l.

Fig. 3 is a section taken on line v3 3 of Fig. 1.

Fig. 4 is a section taken on line 4-4 of Fig. 1.

The iilter consists of three quickly and easily replaceable units, respectively, the iilter unit, the

container, and thesupport. v

The filter unit consists of a triple dome shell 'with the upper :dome lil forming the vdistribution chamber for the fluid to beiiltered, and has a supply pipe II adjustable through a stop cock z|2 secured in the upper end of the'dome and terminating in a nozzle I3.

VThis upper dome I0 continues into the enlarged Vmedian dome I4 which 'is iilled with a suitable seated against the bottom ofthe upper collar i9' and sealed in place by a special cement 23 which in turn is locked inplace by the lower collar 20. This disc `may be vmade of any suitable ltering material, fpreferablyof a molded and fused material, one such material being a ne mesh Alun'dun'i.l The cement used-is one which contains no soluble elements and which will form a perfect seal to direct all liquid through the disc. The inverted frusto-conical form of the lter disc is particularly suitable for this method of sealing andanchorin'g. It will be noted that the granular filtering material 24 is supported by this disc, therefore the disc simultaneously functions as a filtering medium and as a support for the granular ltering material.- The actual form of this dome is a` cylinder with spherical upper end.

This median dome continues into the lower dome 25 which has an exterior annular collar 26 to seat on the top of the container 2l, and is located in spaced relation above the bottom 28 of the lower dome. Two annular collars 29 Iand 3U are formed `interiorly ofthe dome, one being at thebottom and the otherin spaced relation above.

60 Projections or beads. 3| are formed in the upper This leaves a free space 34,v

drain pipe to seat, and the filter unit is placed in the top of the container.

In the drawing, the container is disproportionately reduced in size, and the upper portion of the lter unit is disproportionately reduced in height.

A source of water under pressure is supplied through the pipe l l and its flow regulated by the member, providing an exceptionally great filtering area.

The container 21 has an opening 35 to receive the lower end of the lter unit, and a suitable spigot 36 is provided in accordance with requirements. The bottom 31 of the container is formed to drainto the center at which point a recess 38 is formed with a central aperture 39.

VA suitable base 40 ,has a planesurface 4I on which the beads 42 formed on the bottom of the container rest, and this portion has an annular collar 43 to form a catch basin vfor condensation which .may drain down the exterior of the container. A sump 44 is formed in the base 40 and this sump has passages 45 leading into the discharge chamber 46 which has a connection 41 to waste, and which connection preferably consists of a trap. Obviously, the base 4D may be provided with a wall bracket, not shown, or with any other desired means of support.

A .combined drain pipe and trap member 48 has an annular collar 49 intermediate its height' and is threaded both, below and above this co1- lar; andvpasses through the central passage in the container with a suitable gasket interposed between the collar 49 and the seat at the bottom of Ythe recess, This pipe extends down into the sump44 t0 a point below the passages 45, thus forming `a trap. I-Ioles 52 are formed diametrically through the pipe 48 just above the collar 49, and the.v p ipe terminates a short distance above these, passages as indicated at 53. A riser or overiiow pipe 54 has a sleeve 55 xed at the lower end and internally threaded to iit the upper threaded portion 53 of the .drain pipe; the main portion of the overflow pipe terminating in spaced relation to the top of the drain pipe as indicated at 51, and extends upwardly nearly to the top of the container, and has suitable means, such as plate or screw driver slots 58y provided at the upper end for screwing the member down to a seal with the collar 3B to seal the passages 52, and for unscrewing the member to uncover these passages 52 to completely drain theV container.

A withdrawal tube 59 extends from the bottom of the container exteriorly of the riser as indicated at Gil, to a point Gl close to the top and inside of the riser, and is indicated as passing through the wall of the riser at 62 at which point it is sealed in the wall.

In assembling the lter unit, the o-pening for the stop cock at the top` is plugged, and the side passages are closed by the cap nuts and. stud. The shell is inverted and filled with the granular lter material about to the height of the stud. The median lter element is then placed in position and sealed in place by lling the peripheral recess with a suitable cement. The last stage filter element is then placed in position and the peripheral recess is lled with the same kind of cement.

rIhe drain pipe is secured in place in the bottom of the container, and the overflow orr riser pipe is screwed down on the upper end of the stop cock I2 to supply the normal amount of ltered water required. This water is subject to very little resistance through thev first lter stage (the loose granular mass), which retains all suspended r'natter.l The resistance through the sectainer.

ond stage is moderate, the element being of suiciently fine mesh or low permeability to retain even the. nest suspensions.` High resistance to iiow per unit area is ,offered bythe third stage which is of extremely fine mesh orextremely low permeability, for which reason its filtering area is very great in comparison to that of the second stage. It will -be noted that the entire superficial area ,exteriorly is accessible to the water whichhas passed through the second stage, and that interiorly, the flat bottom endof the filter element functions along with the cylindrical and spherical areas.

When the container becomes filled to the top of thewithdrawal tube 59, water passes from the bottom of the container up through this tube and out through the top into the riser, thence down through the riser into the trap 44, forming a seal against extraneous air or gases, the water passing from the trap to waste through the pipe 41. If the flow should become unduly excessive, the excess will overflow into the riser, however, the preferred withdrawalis from the bottom of the con- If` the containeris to be drained, the lter unit is removed from the top of the container and the riser is unscrewed to uncover the passages 52, through which the container will be completely drained.

'I he second and last stage filter elements appear to never require cleaning or replacement. The rst stage is easilycleaned by inverting the unit, removing the cap nuts and the stud, and passing a strong current of water upwardly from the stop cock, then replacing the stud and cap nuts, when it is again ready for use.

This first stage is also easily replaced by merely removing the. cap nuts .and stud and washing the materia1 out through the passages by a stream of water from the stop cock, thereafter inverting the unit and vrefilling with filter material through these passages, then replacing the stud and cap nuts, Y

I claim:

1.1.A filter, in combination, a container having an overflow passage and a trap therefor; a threestage filter unit of relatively decreasing permeability and supported by and .discharging-into said container, and an inlet for liquid under pressure. and connected to the initial one of said three stages,`and flow control means for said inlet; said overow passage comprising; a pipe fixed in the bottom of said container and having an upward extension provided with diametric passages opening into the lower portion of said container, and a downward extension terminatingin a sump to form said trap; and a second pipe having vits lower end telescopically associated with said upward extension and adjustable toppen and close said passages for draining the container or for sealing the passages atwll; a tube extending from the' lower portion of said container exteriorly of said second pipe'to a point near the top and within said second pipe,

for draining excess ltrate from the lower portion of the body of filtrate in the container.

2. A filter, in combination, a container having an overflow passage and-a trap therefor; a threestage iilter unit of relatively decreasing permeability and supported by and discharging into said container, and an inlet for liquid under pressure and connected to the initial one of said three stages, and now control means for said inlet; said filter unit comprising; a cylindrical casing terminating at its lower end in a dome shaped portionof greater diameter; said ow control means being connected at the upper end of said cylindrical casing; a partition mounted in said cylin-l drical casing above the level of communication with said dome shaped portion and consisting of a molded section of filter material of medium permeability; a granular lter material in said cylindrical casing above and supported on said partition; a dome shaped filter element formed of filter material of low permeability and mounted in said dome shaped portion and sealed thereto at the lower end with the exterior periphery above the seal clearing the walls of said dome shaped portion for access of liquid, with the discharge side formed by the lower surface and interior of the dome; said dome shaped lter element having an area greater than that of said partition inv A conformity with the difference in permeabilities.

3. A lter comprising; a container having an outlet at the bottom thereof and a trap for said outlet, and a riser in communication with said outlet for passing great excesses of ltrate to said trap by overflow, and a tube extending from the bottom of said container exteriorly of said riser to a point adjacent thetop within `said riser to pass normal excesses of liquid from the lower portion of the body of I:Filtrate within the container to said trap; a lter unit mounted in the top of said container, and an outlet for liquid under pressure for said filter unit.

4. A structure as defined in claim 3; said filter unit comprising; a casing including a vertical cylindrical section closed at the upper end and terminating at the lower end in a dome-shaped shell open at the bottom; a partition sealed within said cylindrical section immediately above said dome-shaped shell and formed of lter material of medium permeability; a supply of loose granular lter material within said cylindrical section and supported by said partition; and a domeshaped form of lter material of low permeability located within said dome-shaped shell and clearing the walls thereof and sealed at the lower end to said walls and having an area greater than said partition proportionate to the differences in permeability.

5. A structure as defined in claim 3; said lter unit comprising a casing including a vertical cylindrical section closed at the upper end and terminating at the lower end in a dome-shaped shell open at the bottom, and a pressure iluid connection for said upper end; a partition sealed within said cylindrical section immediately above said dome-shaped shell and formed of lter material of medium permeability; a supply of loose granular lter material within `said cylindrical section and supported by said partition; a domeshaped form of lter material of low permeability located within said dome-shaped shell and clearing the walls thereof and sealed at the lower end to said walls and having an area greater than said partition proportionate to the differences in permeability; and passagesformed through the opposite walls of said cylindrical section immediately above said partition for removal, replacement, or cleaning of said granular material, and means manually releasable for sealing said passages.

6. A lter unit comprising; a lower domeshaped shell open at the bottom; a median cylindrical shell opening into the top of said domeshaped shell and extending upwardly; an upper cylindrical shell opening into the top of said median shell and extending upwardly and sealed at the upper end and having a connection for a source of liquid under pressure; a molded section of lter material peripherally sealed within said median shell in slightly spaced relation above the upper end of said dome-shaped shell and forming a partition, with the median shell lled with loose granular filter material and supportedv on said partition; and a dome-shaped form of molded lilter material located within said lower shell and peripherally sealed at the lower end to said shell with the exterior surface clearing the interior surface of the shell for accessibility of liquid.

'7. A structure as defined in claim 6; diametric passages formed through the opposite walls of said median cylindrical shell directly above said partition, for removal, replacement, or cleaning of said granular lter material, and releasable sealing means for said passages.

8. A structure as dened in claim 6; an annular flange formed exteriorly of said domeshaped shell in spaced relation above the lower n end and forminga support for theunit on av container for the ltrate.

9. A structure as deiined in claim 6; diametric passages formed through the opposite walls of said median cylindrical shell directly above said partition, for removal, replacement, or cleaning of said granular lter material, and releasable sealing means for said passages; an annular flange formed exteriorly of said dome-shaped shell in spaced relation above the lower end and forming a support for the unit on a container for filtrate.

10. A structure ras dened in claim 6; vertically spaced annular rings formed interiorly of said median cylindrical shell immediately above the lower end thereof with the upper peripheral edge of said partition resting against the under surface of the upper ring, and with the space between the rings and between the peripheral surface of the partition and the shell filledu with cement whereby the partition is peripherally sealed.

11. A structure as dei-ined in claim 6; two annular rings formed interiorly of said domeshaped shell with one ring located at the bottom of the shell and the other in spaced relation above, beads formed inwardly at the upper end of said dome shaped shell adjacent to the opening into the median cylindrical shell; said domeshaped form being exteriorly beveled at its lower end, with the space between the bevel and shell and between the annular rings iilled with cement to form the seal for the form with the lower ring locking the cement against displacement; said form being spaced from the shell by the upper of said rings and by said beadsto provide space for liquid about the entire superficial exterior area of the form.

WlLLIAM B. PUMPHREY. 

